High-entropy alloy nitride film for medical instrument and preparation method therefor

Abstract

The present invention relates to the technical field of coatings and provides a high-entropy alloy nitride film for a medical instrument and a preparation method therefor. The present invention provides a high-entropy alloy nitride film for a medical instrument. The method comprises the following step: carrying out magnetron sputtering on a TiZrTaWVNb alloy target to obtain the high-entropy alloy nitride film on the surface of a substrate, wherein the magnetron sputtering is carried out in a flowing atmosphere; the atmosphere comprises a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; and the flow rate of the nitrogen is 3-25 sccm. In the present invention, by adjusting the type of a high-entropy alloy and the flow rates of the nitrogen and rare gas, the toughness and hardness of the high-entropy alloy are improved.

Description

A high-entropy alloy nitride film for medical devices and its preparation method Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a high-entropy alloy nitride film for medical devices and its preparation method. Background Technology

[0002] The toughness and hardness of a material are related to its surface condition; surface treatment can effectively improve these properties. Compared to alloying, surface treatment is simpler and less expensive. Therefore, improving the properties of titanium alloys using surface modification techniques has become a research hotspot.

[0003] High-entropy alloys are composed of five or more metallic or non-metallic elements in equimolar or near-molar ratios, with each element comprising 5% to 35% of the total content. In the preparation of high-entropy nitride alloys from high-entropy alloys, nitrogen gas is typically introduced into the cavity. For example, Braic V et al. prepared (TiZrNbHfTa)N multi-component nitride and (TiZrNbHfTa)C carbide coatings on Ti6Al4V alloys by co-sputtering transition metal targets (Ti, Zr, Nb, Hf, Ta) in a reactive atmosphere (Braic V, Baleanu M, Braic M, et al. Characterization of multi-principal-element(TiZrNbHfTa)N and(TiZrNbHfTa)C coatings for biomedical applications[J]. Journal of the Mechanical Behavior of Biomedical Materials, 2012, 10:197-205.). However, existing high-entropy alloy films still suffer from insufficient hardness and toughness.

[0004] Summary of the Invention

[0005] The purpose of this invention is to provide a high-entropy alloy nitride film for medical devices and its preparation method. The high-entropy alloy nitride film prepared by this invention has high hardness and good toughness.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing a high-entropy alloy nitride film for medical devices, comprising the following steps:

[0008] The high-entropy alloy nitride film was obtained on the substrate surface by magnetron sputtering of TiZrTaWVNb alloy target.

[0009] The magnetron sputtering is performed in a flowing gas atmosphere;

[0010] The gas includes rare gases and nitrogen; the flow rate of the rare gases is 15–60 sccm; and the flow rate of the nitrogen is 3–25 sccm.

[0011] Preferably, the vacuum degree of the magnetron sputtering is less than 4 × 10⁻⁶. -3 Pa, with a power of 80-190W.

[0012] Preferably, the working gas pressure of the magnetron sputtering is 0.4 to 1 Pa, and the sputtering time is 30 to 100 min.

[0013] Preferably, the matrix comprises one of metal, cemented carbide, and single-crystal Si.

[0014] Preferably, before magnetron sputtering, the process further includes polishing and cleaning the substrate.

[0015] Preferably, the cleaning process includes: immersing the substrate successively in ethanol and acetone for ultrasonication, followed by ion cleaning.

[0016] Preferably, the frequency of the ultrasound is independently 15–30 kHz; and the time is independently 10–15 min.

[0017] Preferably, the ion cleaning is performed in a protective atmosphere, with a vacuum degree of 2-4 Pa, a time of 10-20 min, and a DC power supply of 80-190 W.

[0018] The present invention also provides a high-entropy alloy nitride film prepared by the preparation method described in the above technical solution.

[0019] This invention provides a high-entropy alloy nitride film for medical devices, comprising the following steps: magnetron sputtering of a TiZrTaWVNb alloy target to obtain the high-entropy alloy nitride film on the substrate surface; the magnetron sputtering is performed in a flowing atmosphere; the atmosphere includes a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; the flow rate of the nitrogen is 3-25 sccm.

[0020] The high-entropy alloy selected in this invention contains Ti, Zr, Ta, W, V, and Nb, all of which are strong nitride-forming elements. After magnetron sputtering, a solid solution of high-entropy alloy nitride is formed, which improves the hardness of the film. The multiple components in the high-entropy alloy nitride form a nanocomposite structure. The phase interface of the nanocomposite structure can inhibit crack propagation, thereby improving the fracture toughness of the film. Attached Figure Description

[0021] Figure 1 shows the deposition rate of the films in Comparative Example 1 and Examples 1-5;

[0022] Figure 2 is a comparison of the elements of the membranes in Comparative Example 1 and Examples 1-5;

[0023] Figure 3 shows the XRD diffraction patterns of the films in Comparative Example 1 and Examples 1-5;

[0024] Figure 4 shows the cross-sectional SEM morphology of the membranes in Comparative Example 1 and Examples 1-5; Figure 4(a) shows the cross-sectional SEM morphology of the membrane in Comparative Example 1; Figure 4(b)-(f) shows the cross-sectional SEM morphology of the membranes in Examples 1-5.

[0025] Figure 5 shows the HRTEM cross-sectional morphology of the membrane in Example 2;

[0026] Figure 6 is a schematic diagram showing the hardness and elastic modulus results of the films in Comparative Example 1 and Examples 1-5;

[0027] Figure 7 is a schematic diagram of the fracture toughness results of the membranes in Comparative Example 1 and Examples 1-5. Detailed Implementation

[0028] This invention provides a high-entropy alloy nitride membrane for medical devices, comprising the following steps:

[0029] The high-entropy alloy nitride film was obtained on the substrate surface by magnetron sputtering of TiZrTaWVNb alloy target.

[0030] The magnetron sputtering is performed in a flowing gas atmosphere;

[0031] The gas includes rare gases and nitrogen; the flow rate of the rare gases is 15–60 sccm; and the flow rate of the nitrogen is 3–25 sccm.

[0032] In this invention, prior to magnetron sputtering, the process preferably further includes polishing and ion cleaning of the substrate. After polishing, the substrate preferably has a flatness (TIR) ​​of <3 μm, a warpage (TTV) of <10 μm, a bending radius (BOW) of <10 μm, and a roughness of <1 nm.

[0033] In this invention, the substrate preferably includes one of metal, cemented carbide, and single-crystal Si.

[0034] In this invention, the cleaning preferably includes: immersing the substrate in ethanol and acetone successively for ultrasonication, followed by ion cleaning; the frequency of the ultrasonication is preferably 15-30 kHz, more preferably 20-25 kHz; the time is preferably 10-15 min, more preferably 12-13 min.

[0035] In this invention, the ion cleaning is preferably performed in a protective atmosphere for a duration of 10 minutes. The DC power supply for the ion cleaning is preferably 180W, and the vacuum level is preferably 2–4 Pa. In this invention, it is preferable to evacuate to a vacuum level of 5 × 10⁻⁶ Pa. -3 After Pa, rare gas is introduced until the vacuum level required for ion bombardment is achieved.

[0036] In this invention, the vacuum degree of the magnetron sputtering is preferably less than 4 × 10⁻⁶. -3 The working gas pressure is preferably 0.4–1 Pa, more preferably 0.5–0.8 Pa; the power is preferably 80–190 W, more preferably 100–150 W, and even more preferably 120–130 W; the sputtering time is preferably 30–100 min, more preferably 40–60 min. The magnetron sputtering is carried out in a flowing atmosphere; the atmosphere includes a rare gas and nitrogen; the flow rate of the rare gas is 15–60 sccm, preferably 25–50 sccm, more preferably 30–40 sccm; the flow rate of the nitrogen is 3–25 sccm, preferably 5–20 sccm, more preferably 10–15 sccm.

[0037] The following detailed description of the preparation method of the high-entropy alloy nitride film provided by the present invention, with reference to the embodiments, should not be construed as limiting the scope of protection of the present invention.

[0038] The preparation, characterization, and measurement instruments used in the embodiments of this invention are as follows:

[0039] JGP-450 magnetron sputtering system, Shenyang Scientific Instrument Research Center Co., Ltd., Chinese Academy of Sciences;

[0040] D8 Advance X-ray diffractometer, Bruker GmbH, Germany;

[0041] Quanta FEG450 scanning electron microscope, FEI Corporation, USA;

[0042] Bruker TI-980 nanoindenter, Bruker GmbH, Germany;

[0043] JXA-8530FPLUS Field Emission Electron Probe Microanalyzer, JEOL Corporation, Japan;

[0044] Tecnai G2 20 high-resolution transmission electron microscope, FEI Corporation, USA.

[0045] Comparative Example 1

[0046] The single-crystal silicon substrate (20mm×10mm×0.65mm in size, with flatness TIR<3μm, warpage TTV<10μm, bending BOW<10μm, and roughness<1nm after polishing) was ultrasonically cleaned for 15min in analytical grade alcohol and acetone using 15-30kHz.

[0047] Ion cleaning: After loading the sample, place it into the sample injection chamber and evacuate to 5×10⁻⁶. -3 After Pa, Ar gas is turned on to maintain a vacuum of 2-4 Pa, and the substrate is subjected to ion bombardment pre-sputtering for 10 minutes. The DC power supply is 180W.

[0048] Evacuate the vacuum chamber to a vacuum level of 3 × 10⁻⁶. -3 The sputtering of TiZrTaWVNb alloy targets with an equimolar ratio was performed at a working pressure of 0.5 Pa, an argon flow rate of 25 sccm, and a nitrogen flow rate of 0 sccm. The sputtering power was 180 W and the sputtering time was 60 min.

[0049] Example 1

[0050] The only difference from Comparative Example 1 is that the nitrogen flow rate is 5 sccm.

[0051] Example 2

[0052] The only difference from Comparative Example 1 is that the nitrogen flow rate is 10 sccm.

[0053] Example 3

[0054] The only difference from Comparative Example 1 is that the nitrogen flow rate is 15 sccm.

[0055] Example 4

[0056] The only difference from Comparative Example 1 is that the nitrogen flow rate is 20 sccm.

[0057] Example 5

[0058] The only difference from Comparative Example 1 is that the nitrogen flow rate is 25 sccm.

[0059] The deposition rates of the films in Comparative Example 1 and Examples 1-5 were calculated respectively, and the results are shown in Figure 1.

[0060] As shown in Figure 1, with the increase of N2 flow rate, the film deposition rate gradually decreased from 83.28 nm / min to 33.77 nm / min.

[0061] The elemental content of the membranes in Comparative Example 1 and Examples 1-5 was measured, and the results are shown in Figure 2.

[0062] As shown in Figure 2: 1) Without the introduction of N2, the content of the five metallic elements in the high-entropy alloy coating ranges from 11.62% to 24.59 at.%, and the prepared TiZrTaWVNb film conforms to the definition of a high-entropy alloy, with the atomic ratio of each element ranging from 5% to 35%. However, due to Ar... + Different sputtering yields for Ti, Zr, Ta, W, V, and Nb lead to different deposition rates, resulting in variations in the elemental content within the high-entropy alloy nitride film. 2) With increasing N2 flow rate, the N content in the high-entropy alloy nitride film increases rapidly before stabilizing. 3) With further increases in nitrogen flow rate, the nitrogen content consistently exceeds 30%.

[0063] XRD tests were performed on the membranes of Comparative Example 1 and Examples 1-5, and the results are shown in Figure 3.

[0064] As shown in Figure 3, when the N2 flow rate is 0, the diffraction peaks of the TiZrTaWVNb film are not sharp and are relatively broad, indicating that the film is in an amorphous state. After nitrogen gas is introduced, the (TiZrTaWVNb)N... x The crystallinity of the film initially increases and then decreases, especially when N2:Ar = 5:25 (TiZrTaWVNb)N x The film exhibits the strongest crystallinity and has a preferred orientation on the (111) plane. In Figure 3, FCC represents the face-centered cubic structure.

[0065] The membrane cross-sections of Comparative Example 1 and Examples 1-5 were observed by SEM, and the results are shown in Figure 4. In Figure 4(a), the SEM morphology of the membrane cross-section of Comparative Example 1 is shown; in Figure 4(b)-(f), the SEM morphology of the membrane cross-sections of Examples 1-5 are shown.

[0066] As shown in Figure 4, the prepared (TiZrTaWVNb)N x The high-entropy alloy nitride film is relatively dense and uniform, and exhibits good adhesion to the substrate. No obvious internal defects were observed. No visible grain features were observed in the cross-sectional fracture of the film when the nitrogen flow rate was zero. The film thickness gradually decreased with increasing nitrogen flow rate, primarily due to the decrease in sputtering rate. Furthermore, it was found that with increasing nitrogen flow rate, the film may transform from an amorphous phase to a crystalline phase due to the formation of nitride structures.

[0067] HRTEM observation of the cross-section of the high-entropy alloy nitride film of Example 2 is shown in Figure 5. As can be seen from Figure 5, the film is well bonded to the substrate. Furthermore, the film is composed of a large number of nanocrystals and amorphous materials. From the electron diffraction pattern of the selected region, the (111), (200) and (220) crystal planes can be observed, indicating that the (TiZrTaWVNb)N film has an FCC structure.

[0068] The hardness and elastic modulus of the membrane cross sections in Comparative Example 1 and Examples 1-5 were measured respectively, and the results are shown in Figure 6.

[0069] As shown in Figure 6, (TiZrTaWVNb)N x The hardness and elastic modulus of the high-entropy alloy nitride film initially increased and then decreased with increasing N2 flow rate. The optimal hardness and elastic modulus were observed at an N2:Ar ratio of 5:25, reaching 20.5 and 210.5 GPa, respectively. Without nitrogen flow, the hardness and elastic modulus of the TiZrTaWVNb high-entropy alloy nitride film were 14.4 and 177.4 GPa, respectively, showing a significant improvement in hardness compared to the substrate.

[0070] Nanoindentation high-load toughness tests were performed on the films of Comparative Example 1 and Examples 1-5 respectively, and the toughness results are shown in Figure 7.

[0071] As shown in Figure 7, with the increase of the nitrogen and argon flow ratio, the membrane toughness first increases and then decreases. When N2:Ar = 10:25, (TiZrTaWVNb)N x The fracture toughness reached a maximum value of 1.41 MPa·m. 1 / 2 .

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a high-entropy alloy nitride film for a medical instrument, characterized by, Includes the following steps: The high-entropy alloy nitride film was obtained on the substrate surface by magnetron sputtering of TiZrTaWVNb alloy target. The magnetron sputtering is performed in a flowing gas atmosphere; The gas includes rare gases and nitrogen; the flow rate of the rare gases is 15–60 sccm; and the flow rate of the nitrogen is 3–25 sccm.

2. The production method according to claim 1, characterized by, The vacuum degree of the magnetron sputtering is less than 4x10 - 3 Pa, and the power is 80-190 W.

3. The production method according to claim 1 or 2, characterized by, The working gas pressure of the magnetron sputtering is 0.4 to 1 Pa, and the sputtering time is 30 to 100 min.

4. The preparation method according to claim 1, characterized in that, The substrate includes one of metal, cemented carbide, and single-crystal Si.

5. The preparation method according to claim 1 or 4, characterized in that, Before magnetron sputtering, the process also includes polishing and cleaning the substrate.

6. The preparation method according to claim 5, characterized in that, The cleaning process includes: immersing the substrate successively in ethanol and acetone for ultrasonication, followed by ion cleaning.

7. The preparation method according to claim 6, characterized in that, The frequency of the ultrasound is independently 15–30 kHz; the time is independently 10–15 min.

8. The preparation method according to claim 6, characterized in that, The ion cleaning is performed in a protective atmosphere, with a vacuum degree of 2-4 Pa, a time of 10-20 min, and a DC power supply of 80-190 W.

9. The high-entropy alloy nitride film prepared by the preparation method according to any one of claims 1 to 8.

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